.main>ul.tree:nth-of-type(1){
    padding-left: 0;
}
/* .main>ul.tree:nth-of-type(1)::before{
    display: none;
}
.main>ul.tree:nth-of-type(1)>li>.item::before{
    display: none;
} */
ul.tree{
    position: relative;
    display: block;
    line-height: 2.5;
    font-size: 14px;
    cursor: pointer;
    padding-left: 25px;
}
/* .tree::before{
    position: absolute;
    left: 5px;
    z-index: 10;
    content: '';
    display: block;
    width: 0;
    height: 100%;
    border: 1px solid #ccc;
} */
.tree .slider{
    overflow: hidden;
    transition: height .3s;
}
.arrow{
    display: block;
    width: 12px;
    height: 12px;
    transform: rotate(-90deg);
    transition: transform .3s;
    margin-right: 6px;
}
.item{
    display: flex;
    align-items: center;
    position: relative;
    padding: 0 10px;
}
.item input[type="checkbox"]{
    cursor: pointer;
}
/* .item::before{
    position: absolute;
    left: -18px;
    z-index: 10;
    content: '';
    display: block;
    width: 15px;
    height: 0;
    border: 1px solid #ccc;
}
.noChildren::before{
    width: 25px;
} */
.item:hover{
    color: #409eff;
    background-color: #f5f5f5;
}
.checkbox{
    white-space: nowrap;
    cursor: pointer;
    outline: none;
    display: inline-block;
    line-height: 1;
    position: relative;
    vertical-align: middle;
    margin-right: 8px;
}
.checkbox input{
    opacity: 0;
    outline: none;
    position: absolute;
    margin: 0;
    width: 0;
    height: 0;
    z-index: -1;
}
.inner{
    display: inline-block;
    position: relative;
    border: 1px solid #dcdfe6;
    border-radius: 2px;
    box-sizing: border-box;
    width: 14px;
    height: 14px;
    background-color: #fff;
    z-index: 1;
    transition: border-color .25s cubic-bezier(.71,-.46,.29,1.46),background-color .25s cubic-bezier(.71,-.46,.29,1.46);
}
.indeterminate .inner:before {
    content: "";
    position: absolute;
    display: block;
    background-color: #fff;
    height: 2px;
    transform: scale(.5);
    left: 0;
    right: 0;
    top: 5px;
}
.inner:after {
    box-sizing: content-box;
    content: "";
    border: 1px solid #fff;
    border-left: 0;
    border-top: 0;
    height: 7px;
    left: 4px;
    position: absolute;
    top: 1px;
    transform: rotate(45deg) scaleY(0);
    width: 3px;
    transition: transform .15s ease-in .05s;
    transform-origin: center;
}
.checked .inner:after {
    transform: rotate(45deg) scaleY(1);
}
.indeterminate .inner{
    background-color: #409eff;
    border-color: #409eff;
}
.checked .inner{
    background-color: #409eff;
    border-color: #409eff;
}